Do not allow GlobalHandles::Create to reuse destoryed nodes (ones from free l...

src/global-handles.cc

Index: src/global-handles.cc
===================================================================
--- src/global-handles.cc	(revision 2717)
+++ src/global-handles.cc	(working copy)
@@ -156,6 +156,10 @@
     if (func != NULL) {
       v8::Persistent<v8::Object> object = ToApi<v8::Object>(handle());
       {
+        // Forbid reuse of destroyed nodes as they might be already deallocated.
+        // It's fine though to reuse nodes that were destroyed in weak callback
+        // as those cannot be deallocated until we are back from the callback.
+        set_first_free(NULL);

[Mads Ager (chromium), 2009/08/19 17:32:07]

Doesn't this leak the nodes on the free list?  Shouldn't you traverse the free
list and free the nodes before you set first free to NULL?

[antonm, 2009/08/19 17:39:32]

I don't think so.  To the best of my knowledge we don't use first_free_ pointer
while cleaning up the list---destroyed nodes are spotted while traversing the
whole list (fyi, I've experimented w/ other approaches, but they buy us nothing
for DOM performance).  Does that sound reasonable?

And just an observation: DESTROYED nodes could 'leak' both before and with my
patch if you destroy node already traversed, but they should be cleaned up on
next path.

         // Leaving V8.
         VMState state(EXTERNAL);
         func(object, par);